Method of finishing castings such as ingot molds



Patented .lu y 12, 1927.

Raye, CO'ATES, as or ou-E-nALrro ..TOWN,;QHIO.."

N0 Drawing. Application filed Jul 18,

'The present invention "relates broadly to metallurgy and more e pecially to a method of finishing castings s'uchas ingot molds or the like; i

Heretofore' in the 'art where large castings are cast in open molds, such as the molds which are used for manufacture of cast iron ingotinol'ds, the upper surface of the metal is usuaily rough because it" is usually in contact with atmosphere only and is not sha'ped' or .smoothed by contact with a matrix wall. In such castings, it is customary to smooth the rough portion of; the'cas'ting by cutting off "or cutting away the roughened surface portion. This is especially true in connection with the manufacture of cast iron ingot molds by using the inverted position for casting, such as is disclosed in my Patent No. 1,376,403, patented May 3,1921.

Heretofore in the art, it has been customary to perform the operation of cutting or sawing away the undesirable portion afterv the mold is completely cooled and has reached atmospheric temperature. hen the casting is first shaken out of the sand flask mold, sand tightly adheres to the surface of the casting, but as the casting cools down, the shrinkage causes the mold sand to loosen and therefore when the ingot molds are out cold, the surface of the ingot is comparatively clean of sand and the mold sand does not interfere with the cutting off operation.

The principal object of the present invention is to reduce the time and expense of the cutting off operation as applied tolarge castings by performing the cutting operation as soon as the casting has solidified and before it has lost its initial heat after solidification.

Another object of the present invention is the method of finishing ingot molds cast in sand molds by cutting the rough portions therefrom after the ingot mold has solidified and before it has lost its initial heat by first removing the mold sand from the surfaces through which the cutting operation extends, and then performing the cutting operation.

Another and more specific object of the present invention is the method of cutting portions from-ingot molds cast in sand molds which comprises 18111OV1112' a narrow band of mold sand from around the casting while the casting retains its initial heat'and then economical one in several respects.

resannua, CALIFORNIA, ASSIGNGR, BY Muslin ASSIGNMENTS,- jrntn ns'rarn or as;

namLrou, nn'onasnn; LATE or YoUNes- V lvrn'rn onos Finis-Hind cAs'rrNGs SUCH asiueor MGLDS.

1924. Serial No. 726,756. Y

cutting the casting'onthe line of the cleared sand. v p I Other and further objects of the present invention will be obvious and will in part be pointed out hereinafter in the specification following.

A more specific disclosure of the present invention will now be set forth and it comprises cutting off the undesired portionsof a cast iron ingot mold as soon as possible after the ingot mold is shakenfrom the sand flask and after the castniold has s'uificiefntlfy solidified to be safe from bleeding. WVhen this stage, of the cast mold is reached the iron is red hot'but is comparatively soft and may be cut at a much higher speed and with considerably less energy than is required when the cast mold is completely cooled. A large amount of mold sand adheres to the red hot casting at this stage and this sand has a deleterious effect on cutting tools because of its abrasive action thereon. In carrying out my method as applied to a hollow casting such as an ingot mold, a narrow band of the mold sand is removed from both the inside and outside of the mold and the cutting tool is then operated over and through this narrow band. The removal operation may be done simultaneously with. but slightly in advance of, the entry of the cutting off tool into the work. This prevents any substantial chilling of the metal over the cutting area or zone. The cutting off and the clearing of the sand may be done by any appropriate devices, such as a hot metal saw and an appropriate cleaning device which proceeds the saw.

By the use ofthe improved method, the sand mold flasks are released for further operations quickly and the cutting operation may proceed with far greater rapidity and with less effort than where the old practice is followed. After the cutting or finish ing iscompleted, the casting with the adhering sand thereon may be annealed in a hot pile or in a special oven according to the practice in the art. The adhering sand greatly retards the cooling of the casting, thus facilitating the annealing.

, it is apparent that the herein disclosed method of finishing castings is a very The undesirable portions are cut off at a red heat, thus economizing in cutting power.

The heat which may be utilized is the original casting heat and hence the expense of reheating may be eliminated. Injury to the cutting tool by sand is avoit ed by cleaning the cutting Zone, but at the same time the sand is retained on the rest of the casting, thus retarding the cooling of the casting during annealing.

From the foregoing, I desire that it he understood that this method is not limited to cutting away merely the bottom part of ingot mold casting, but is adaptable for use in cutting or finishing either end of such ingot mold, or the like, dependent upon Whichever end of the ingot mold contains that portion Which requires cutting away or finishing.

Having thus described my invention, what I claim is:

1. The method of finishing large *astings cast in sand molds, comprising taking the casting from the flask as soon as the metal in the casting has set, removing the adhering sand throughout a zone Where the casting is to be cut, and severing undesirable portions from said casting by cutting through the sand cleaned Zone immediately after the removal of the casting from the flask and before the initial heat of the metal has dissipated suificiently to cause the casting to completely harden.

2. The method of finishing ingot molds or the like cast in sand molds, which method comprises mirroring the ingot mold from the flask as soon as the metal has set and sawing away undesired end portions While the ingotmold is retained at red heat by the initial heat of the metal, annealing the ingot mold and utilizing the adhering sand to re tard the rate of cooling during annealing.

3. The method of finishing cast iron ingot molds cast in a sand matrix which method comprises removing the ingot mold from the flask as soon as the metal in the ingot mold has solidified, then removing the adhering sand from a portion of the inside wall and the opposite portion of the outside wall of the ingot mold, severing the end from the mold by cutting at right angles to the axis 01' the ingot mold through the surfaces from which the adhering sand has been removed, annealing the finished ingot mold and utilizing the adhering sand to retard the rate of cooling during annealing.

RAY e. COATES. 

